1. Field of the Invention
The present invention concerns a novel composition of ingredients which are used as an additive to a combustible liquid fuel to produce a clear stable solutions or microemulsions with the fuel. The additive meets or exceeds liquid property specification requirements of the combustible fuel and greatly improves the overall combustion of the fuel while reducing significantly unwanted smoke, particulates, toxic gases, noxious gases and the like. Specifically the additive composition includes one or more of the following: aqueous, or anhydrous water-soluble alcohols and includes optionally one or more of the following: water-insoluble alcohols; ethoxylated alcohols; and fatty acids partially neutralized with a volatile source of basic nitrogen, while specifically limiting the use of ethylene oxides and specifically excluding conventionally used glycerine, esterification products, metals, non-biodegradable solvents, and certain other components.
2. Description of Related Art
Much research, effort and time have been expended to produce fuel compositions for internal combustion engines which show significant decreases upon combustion of toxic exhaust gases or vapors, particulates, smoke, and the like without sacrifice of engine performance or efficiency.
It is currently known by those skilled in the art that the introduction of oxygenators into fossil fuels contributes to better burning and the reduction of toxic exhaust emissions. Ethanol is one such oxygenator which, when used with gasoline for instance, reduces toxic emissions.
A problem, however, is that ethanol attracts water and will separate from gasoline in the presence of certain amounts of water condensation. Another problem is that ethanol is generally denatured using methanol, which exacerbates the problem of water separation and produces unacceptable solvency levels, such that ethanol/methanol/gasoline mixtures cannot be transported through existing pipelines. The present invention solves the problem of water condensation in the presence of ethanol/gasoline mixtures by creating clear microemulsions that are bio-degradeable, do not separate, and actually make use of small amounts of water for superior combustion temperatures. The present invention also solves the problem of solvency levels of ethanol/gasoline mixtures by utilizing components that meet storage and shipping requirements for gasoline.
Another problem associated with using ethanol as an oxygenator is that ethanol, as well as methanol and other water-soluble alcohols, will not mix at all with less refined fossil fuels, such as Diesel fuel or other distillate fuels like kerosene.
The present invention makes it possible to introduce ethanol into Diesel and other distillate fuels, forming bio-degradable clear, stable solutions and microemulsions that will absorb water condensation for optimal combustion temperatures and uses other water-soluble alcohols for their oxygenating properties.
There are many components which when mixed together form emulsions with liquid hydrocarbons, fuels, refined renewable resources (vegetable oils) and the like. However, most mixtures of components do not meet the present set of fuel storage and combustion regulations and engine performance parameters.
These requirements include, for example:
A fuel/additive composition must form a clear, stable, water-in-oil microemulsion where water and water-soluble components are very finely dispersed throughout the continuous phase which must be the oil phase.
In order for efficient combustion to occur, the flame front in the combustion chamber must contact oil first to maintain optimum combustion temperature. The presence of any water at all will reduce combustion temperature. The presence of an optimal amount of water and water-soluble alcohol inside the oil droplet (in the micelle of the micro-emulsion) produces balanced, optimal fuel/oxygen ratios and combustion temperatures where carbon present is more completely burned.
When this slightly reduced but still high level of heat reaches the extremely fine water droplet, the water is transformed into steam. The expansion of liquid water to steam (at a ratio of 1:600) also produces power of its own, which further enhances engine performance.
On the other hand, an oil-in-water emulsion will not perform in the same way. With water as the continuous phase, water contacts the flame front first. The water diminishes or puts the fire out, and then the smoldering flame contacts oil. The results of this incomplete combustion are extremely high hydrocarbon (unburned fuel), particulates, smoke, etc. emissions and significantly reduced power. Nitrogen oxides are usually reduced; however, that is because the temperature of combustion is also reduced below any efficiency level.
Diesel engines are particularly suited to fuel/additive combustion enhancement. Compression ignition engines rely on the heat of compression to produce combustion of fuel; however, it is the compression and expansion of air that is the important power dynamic which makes Diesel engines highly effective.
Fuel/additive power enhancement works on the same principle. At the top of the compression stroke, a small amount of fuel/alcohol/water mixture ignites and explodes. The fuel bums, and now both air and steam expand together to produce power.
Fuel/additive combustion enhancement is made possible by the presence of increased oxygen levels provided by water-soluble alcohols and water. An optimal fuel:oxygen ratio is produced allowing for the complete combustion of available carbon.
The same principle works in a gasoline, spark-ignited engine. As spark-ignited engines are designed, power comes only from the expansion of the explosion of gasoline which is limited compared to the power produced by the compression and expansion of air. The fuel/additive gives these relatively low-efficiency engines the benefit of the water to steam expansion as well as improved oxygenation for more complete burning of carbon.
Even though they produce much greater power levels, the emissions problem associated with Diesel engines has always been difficult to solve. Diesel fuel is usually too rich in hydrocarbons to maintain the delicate balance required for optimal power and complete burning of carbon. Without modification, Diesel fuel burns incompletely. Diesel fuel contains too much carbon in relation to the amount of available oxygen and for what it has to accomplish in the split second before the piston starts moving away from its highest compression (heat) point.
The addition of certain oils, alcohols, and water produce an efficient combination and combustion is extremely enhanced. Vegetable-based components and most alcohols have slightly lower cetane (BTU) value than other fuels. However, water and water-soluble alcohols increase available oxygen and maintain optimal temperatures in the combustion chamber so that essentially all available carbon is burned and utilized for power, rather than being emitted as carbon particles in exhaust smoke. At the same time, water enhances power through expansion as steam and cleans engine parts with its detergent properties.
Although some of the following components may be useful in producing clear, stable microemulsions, they cannot be included in a formulation intended for use as a fuel in an internal combustion engine.
The U.S. Environmental Protection Agency (EPA) specifically rules against fuel compositions with sulphur, aromatic hydrocarbons, and metals of any kind because of the resulting detrimental emissions byproducts. To meet EPA and California (Calif.) Air Resources Board (CARB) standards only the elements carbon, hydrogen, oxygen, or nitrogen (CHON) can be included.
For instance, sodium or potassium salts in the presence of fatty acids also form a microemulsion, but do not fall into the CHON classification, and also cannot be used because of excessive corrosive properties.
Even among possible components that fall within the CHON classification, many are still unsuitable for the intended use. For example, ethylene oxides enhance microemulsion stability, but impede combustion, and can be used only in very limited amounts.
Even among possible CHON components that show promising combustion qualities, many are still unsuitable for optimum performance. For an additive composition to be useful it must meet these qualifications:
1. It must be stable at high and low temperatures.
2. It must maintain a viscosity similar to fossil fuel in all temperature and pressure conditions.
3. It must not damage engine or fuel system parts.
4. It must be usable with little or no retrofit of engine or fuel system parts.
5. It must maintain a power level suitable to its particular application.
6. It must show an improvement in engine performance or emissions and preferably both.
7. It must not increase nitrogen oxides or hydrocarbon or carbon monoxide emissions.
Methyl esters are often used as a fossil fuel additive; however, glycerides must be removed during the esterification process, reducing and even eliminating, cost effectiveness. Gelling problems hamper their use, especially at low temperatures, and typically, methyl esters have been producing about a 5% increase in nitrogen oxides in older engines, making them unusable as far as the EPA and its regulations is concerned.
Another fuel additive is a water emulsion using naptha as its base fuel. The purpose is to reduce NOx emissions. The composition uses as much as 40-50% water. Not only does an extra fuel tank need to be installed to carry the added liquid, hydrocarbon emissions (incomplete combustion) increase dramatically as the combustion flame front hits water. NOx emissions are also reduced, but that is because there is essentially insufficient combustion to cause a nitrogen/oxygen reaction.
Another fuel additive is methyltetrahydrofuran which is currently under study as a possible additive to introduce ethanol into Diesel fuel. However, methyl-tetrahydrofuran is a highly aggressive solvent known to attack and dissolve various metals, creating a high probability for damage to engine parts if used as a fuel in existing engines.
Another fuel additive is methyl tertiary butyl ether (MTBE) which successfully improves combustion characteristics of gasoline. However, MTBE is currently under investigation by the EPA, having been shown to be a toxic groundwater contaminant. As a result, its use is banned in several states.
Some prior research in the field includes, but is not limited to:
E. Wenzel et al. in U.S. Pat. Nos. 3,608,530 and 5,025,759 disclose a compression ignition (Diesel) engine having paired opposed cylinders and a lever system interconnecting the pistons of the opposed power cycle cylinders with each other and with a crank shaft. Together, the long-stroke opposed-cylinders and smooth rotary type connection to the crankshaft produce optimal combustion efficiency and optimally balanced mechanical efficiency. However, even in this efficiently designed engine, standard Diesel fuel will produce unacceptable levels of emissions and by-products under current and planned EPA regulations. On the other hand, the present invention described herein below discloses a stable fuel composition for reducing Diesel fuel emissions as well as incorporating components derived from renewable resources to augment dwindling fossil fuel supplies.
E. Wenzel et al. in U.S. Pat. No. 4,083,698 disclose a clear stable liquid fuel composition for internal combustion engines. The fuel composition comprises a water-in-oil (w/o) emulsion of (a) a hydrocarbon fuel, (b) water, (c) a water-soluble alcohol and a combination of surface active agents, which are stable emulsions over a wide range of temperatures. However, in all described aspects, a non-ionic surfactant is a necessary component of the additive. In all described aspects this non-ionic surfactant includes an ethylene, polyethylene, polyoxyethylene and/or polyoxypropylene addition product.
A. W. Schwab et al. in U.S. Pat. No. 4,451,267 disclose microemulsions for vegetable oil and aqueous alcohol with a trialkylamines surfactant as an alternative fuel for Diesel engines.
A. W. Schwab et al. in U.S. Pat. No. 4,526,586 disclose microemulsions from vegetable oil and aqueous alcohols with 1-butanol and optionally trialkylamines as an alternative fuel for Diesel engines. There is no disclosure in U.S. Pat. No. 4,451,267 or U.S. Pat. No. 4,526,586 in which the vegetable oil emulsion is mixed with hydrocarbon fuels to form a water in oil (w/o) microemulsion with a hydrocarbon fuel.
W. Fridreich et al. in U.S. Pat. No. 4,732,576 disclose a motor fuel and fuel oil emulsions using an organic salt as an emulsifier. Specific amine polyether diacid salts are a necessary component of the additive.
J. W. Foresberg et al. in U.S. Pat. No. 5,360,458 disclose water-oil emulsions comprising-water, oil, and a minor emulsifying amount of the reaction product of at least one saturated or unsaturated aliphatic monocarboxylic acid of about 12 to 24 carbon atoms. In all aspects, at least one acid of the general formula C19HnCOOH wherein n is between about 27 and 31 and having a phenanthrene nucleus and at least one amine are present as necessary components. In all aspects an aromatic hydrocarbon is a necessary component of the additive.
S. G. Schon et al. in U.S. Pat. No. 5,004,479 disclose stable microemulsion fuel compositions which comprise (a) a hydrocarbon fuel such as Diesel fuel, jet fuel, gasoline, fuel oil, etc.; (b) water; and (c) a cosurfactant combination of methanol and a fatty acid which is partially neutralized by a nitrogenous base. In all aspects of U.S. Pat. No. 5,004,479, methanol is the only alcohol present. Some U.S. Patents of general background interest include:
U.S. Pat. Nos. 4,406,519 and 4,451,265.
Other references of general background interest include:
J. J. Donnelly, Jr. and H. M. White, “Water and Alcohol Use in Automotive Diesel Engines” DOE/DX/50286-4 published September 1985.
A. L. Compere et al., “Microemulsion Fuels: Development and Use” ORNL TM-9603, published March 1985.
W. D. Weatherford, Jr. et al., AFLRL Reports 111, 13, 145, U.S. Army Fuels and Lubricants Research Laboratory.
None of these patents, references, or articles teach or suggest the present invention.
All patents, patent applications, articles, references, standards, etc. cited herein are incorporated by reference in their entirety.
In spite of the present state of the art, a need still exists for improved fuel/additive compositions which:
1. do improve combustion and reduce or eliminate smoke, particulates and noxious gases;
2. do not damage engine or fuel system parts;
3. are usable with little or no retrofit of engine or fuel system parts;
4. are usable in varying proportions according to the requirements of various applications;
5. meet federal EPA and state Air Resources Board standards; and
6. make use of renewable and readily available resources to partially or fully replace fossil-based fuels.
The present invention provides such a range of improved compositions.